On 16 February 2014, it was reported that Slomka became head coach of Hamburger SV pending the approval of the supervisory board. It was approved and announced the following day. He was given a contract until 2016. He is the 13th head coach of Hamburg since 2004. Slomka's first match in charge was a 3–0 win over Borussia Dortmund. Slomka was able to pick up two more victories (1. FC Nürnberg and Bayer Leverkusen). He didn't pick up a single point over the final five matches of the league season. This includes losses to Hannover 96, VfL Wolfsburg, FC Augsburg, Bayern Munich, and 1. FSV Mainz 05. Despite not picking up any points over this period, 1. FC Nürnberg and Eintracht Braunschweig were unable to catch Hamburg and they finished the season in 16th place, which led to a relegation–promotion play–off against Greuther Fürth. In the relegation–promotion play–off, the first leg ended in a 0–0 draw and the second leg ended in a 1–1 draw. The result meant that Hamburg avoided relegation. Slomka was sacked on 15 September 2014 after only one point and no goals in the 2014–15 Bundesliga season. Slomka launched a lawsuit against Hamburg for €1.4 million compensation.